As the largest, strongest and heaviest joints in the body, knees provide support and mobility. They also carry almost half the body's weight.
Knees function like a hinge. The lower end of the femur (thighbone) rotates on the upper end of the tibia (shinbone) and patella (kneecap). A healthy knee lets you move your lower leg forward and backward, and swivel slightly to point the toes in or out. Ligaments and cartilage stabilize and support the joint, preventing it from moving too far from side to side.
If osteoarthritis wears away a knee joint's articular cartilage, your doctor may recommend total knee arthroplasty (replacement). Total knee replacement is a common and successful procedure that improves motion of the joint. It lets you resume relatively normal activities without pain.
Knee replacement surgery is generally recommended for patients with severe knee pain and disability caused by damage to cartilage from rheumatoid arthritis, osteoarthritis, or trauma. It is highly successful in relieving pain and restoring joint function.